Earticle

본 연구는 청동기시대 중기 송국리문화의 확산과정에서 만경강 유역의 지역성 을 살펴보기 위하여 적색마연토기에 주목한다. 적색마연토기의 형식 및 분포, 출토 맥락을 기반으로 만경강 유역 적색마연토기의 보편적인 성격을 확인하였으며, 기 종별 출토 비율과 변동계수 분석을 통하여 취락군 간 생산 규범의 차이를 살펴보 았다. 먼저, 만경강 유역 내 취락군이 가장 밀집한 전주천 일대의 세 취락군의 적색마 연토기와 무문토기의 변동계수를 비교한 결과, 취락군 별로 다양한 생산 규범이 추 정되었다. 이는 각 취락군이 토기 생산에 있어서 상이한 기술적 전통을 가졌거나 토기 제작에 대한 사회적 합의에서 차이가 있었을 가능성을 시사한다. 다음으로 적색마연토기를 통해 만경강 유역과 인접한 금강 유역의 사회적 경계 를 검토하였다. 두 수계는 지리적으로 인접해있음에도 불구하고 강경천·산북천 유역에 속하는 익산지역을 경계로 핵심 기종 구성과 의례적 사용에서 뚜렷한 차이를 가지고 있었던 것으로 추정된다. 이는 만경강 유역이 송국리문화를 수용함에 있어 능동적으로 선택하고 재해석하여 독자적인 지역문화를 형성하였음을 보여준다.

This study focuses on Red-burnished Pottery to examine how the Mangyeong River Basin formed its regionality during the diffusion of the Songguk-ri Culture in the Middle Bronze Age. To this end, this paper first identified the general characteristics of Red-burnished Pottery in the Mangyeong River Basin based on an analysis of its typology, distribution, and archaeological contexts. Subsequently, the Coefficient of Variation (CV) was analyzed to compare differences in production norms among settlement clusters. First, a comparison of the CV values for Red-burnished Pottery and Plain Coarse Pottery from the three settlement clusters along the Jeonjucheon Stream revealed distinct production norms for each cluster. This suggests the possibility that each settlement cluster possessed different technical traditions or had different social agreements regarding pottery production. Next, a review of the social boundaries between the Mangyeong River Basin and the adjacent Geum River Basin was conducted using Red-burnished Pottery. The results confirmed clear differences between the two river systems, despite their geographical proximity, particularly in their core typological compositions and ritual practices. This demonstrates that the Mangyeong River Basin actively selected and reinterpreted the Songguk-ri Culture rather than passively accepting it, thereby forming a distinct regional culture.

This study aims to evaluate the ultimate shear strength of the connections of composite steel beam(CSB) composed of reinforced concrete (RC) column and steel beam. Total number of specimens of CSB were 66 carried out by researchers in domestic and foreign countries. The specimens were considered with various types of shear reinforcement such as shear reinforcement of vertical and end concentration, band plate and stud bolt and welding of main bar, etc. Ultimate shear strength of the connections with various reinforcement types was evaluated through experiments and code equations. In this study, experimental result were compared with code formula(KBC-RC, JIS-RC, JIS-SRC) and Zsutty`s Equation. The average test-to-code ratio of ultimate shear strength for all specimens was 1.05(KBC-RC), 1.59(JIS-RC), 1.16(JIS-SRC), and 0.96(Zsutty). Categorized by shear reinforcement type of specimen, ultimate shear strength by code formula and Zsutty’s equation deviated from 6% to 41% from experimental results and the average of deviated percentage was 25%(KBC-RC), 29%(JIS-RC), 29%(JIS-SRC), and 21%(Zsutty). Specimen reinforced at end with fixed plate showed the best correlation with code formula and Zsutty’s equation.

The purpose of this study is to evaluate the Chloride ion migration coefficient of High-heated Concrete by NT BUILD 492 method. To evaluate performance of surface 5cm incoming Chloride Ion, 2D-numerical analysis model (FEM) was developed. As results of this study was obtained as follows; The Chloride ion migration coefficient of High-heated Concrete were increased by heated temperature. In conclusion, the Chloride ion migration coefficient were affected by distribution of porosity and pore size.

본 연구는 중학교 남자 투창 선수들의 기록수준별 창던지기 동작에 대한 운동학적 분석을 통하여 기록에 영향을 미치는 요인을 규명하고자 하였다. 이러한 목적을 달성하기 위하여 제 47회 전국소년체육대회에 참여한 중학교 남자 선수들이 수행한 창던지기 종목을 2대의 비디오카메라로 촬영 후 결선에 진출한 선수 8명과 결선에 진출하기 못한 선수 8명에 대하여 3차원 동작 분석을 실시하였다. 기록 수준에 따른 운동학적 변인 차이를 규명하기 위하여 SPSS 20을 이용하여 독립 t 검증을 실시하였다(p<.05). 그 결과 결선진출 집단이 결선미진출 집단에 비해 투사속도, 스트라이드길이, 릴리즈 시 무릎각도에서 크게 나타났고, 공격각과 창의 자세각에서는 작게 나타났다(p<.05). 창의 공격각도, 릴리즈 시 창그립과 파울라인 거리, 무게중심의 수직속도 변화에서 변동계수가 크게 나타났다. 이러한 결과를 요약하면 중학교 남자 선수들의 기록 향상을 위해서는 동작의 일관성을 유지하면서 마지막 스트라이드 길이를 길게 하고 지지발 착지 시 무릎각을 최대로 신전시키면서 창의 자세각을 낮추어야 한다.

The purpose of this study was to analyze the kinematic characteristics of javelin throw by record level in middle school male athletes. To accomplish these purpose, we filmed javelin throwing event in the 47th National Junior Sports Festival using two cameras, divided 16-athletes into two groups(higher rank group, lower rank group) by record level, and fulfilled 3-D motion analysis. To verify statistical significance between two groups by record level, t-test was conducted using SPSS 20(p<.05). As a result, higher rank group of 8 athletes showed higher values in release velocity, stride length, knee angle at release than lower rank group(p<.05). On the other hands, Attack angle and attitude angle of javelin was smaller(p<.05). In coefficient of variation, attack angle of javelin, javelin grip distance (release to foul line), vertical velocity change volume of center of gravity was higher values. After all, to develop record of middle school male athletes they should maintain consistency of movement and make lower attitude angle of javelin, make longer last stride length and extend knee angle maximally at support’s foot ground contact.

This study is to analysis on the Annual Expenditures Disparity of the Special Account for Educational Expenses by utilizing each fiscal year coefficient of variation method. According to the study, as well tuition per student for the educational core services, education expenses, facility expenses and try to improve schooling conditions for the Human Resources Department gap between operating costs to support the qualitative improvement of education showed gradual increases. A discussion of the findings and recommendations are as follows. First, it attempts local office of education increased the gap between provincial education budget allocation is contrary to the principles of equity. Second, there is a growing gap between the educational core services. Instrucational expenses woke learning gap will appear larger, which appeared to exhibit a high correlation with the municipal operations. Third, it attempts to local office of education growing gap between the facility fee is required funding and allocation plan in accordance with a separate standard. Fourth, the efficient and rational management of the appropriations try DOE is required. Since 2015 the local education budget is implemented and will be evaluated in each local office of education to strength of accountability for financial management. Fifth, the provincial education funding gap of operation, equity and adequacy discussion needs to be expanded on an ongoing basis. Sixth, the difference between the school board, local educational finance a comprehensive gap analysis taking into account the differences within the Department of Education is required.

In this paper we have suggested a family of chain estimators of the population mean $\bar{Y}$ of a study variate y using two auxiliary variates in two phase (double) sampling assuming that the coefficient of variation of the second auxiliary variable is known. It is well known that chain estimators are traditionally formulated when the population mean $\bar{X}_1$ of one of the two auxiliary variables, say $x_1$, is not known but the population mean $\bar{X}_2$ of the other auxiliary variate $x_2$ is available and $x_1$ has higher degree of positive correlation with the study variate y than $x_2$ has with y, $x_2$ being closely related to $x_1$. Here the classes are constructed when the population mean $\bar{X}_1\;of\;X_1$ is not known and the coefficient of variation $C_{x2}\;of\;X_2$ is known instead of population mean $\bar{X}_2$. Asymptotic expressions for the bias and mean square error (MSE) of the suggested family have been obtained. An asymptotic optimum estimator (AOE) is also identified with its MSE formula. The optimum sample sizes of the preliminary and final samples have been derived under a linear cost function. An empirical study has been carried out to show the superiority of the constructed estimator over others.

In order to determined the appropriate processing season of Pacific oyster (Crassostrea gigas), 30 individuals cultured in Kamak Bay on the southern coast of Korea were taken bimonthly 7 times a year, and seasonal variation of edible portion weight, edible portion yield and coefficient of fatness were investigated. There were close relationships between edible portion weight (X) and total weight (Y) and between coefficient of fatness (X) and edible portion yield (Y), which were expressed in regression lines, i.e. Y=0.2709X-1.9094 (r=0.9254) and Y=44.0596X+ 15.1127 (r=0.8485), respectively. From the results of seasonal variation of edible portion weight, yield and coefficient of fatness, the appropriate processing season of raw Pacific oyster was between winter and spring, that is, between December and following April the next year.

In this paper, the means of the estimators for the coefficient of variation (CV) in an underlying Pareto distribution are expressed in terms of confluent hypergeometric functions. The numericla values of the biases for the CV estimators in the Pareto distribution are also obtained.

An approximate distribution of the plug-in estimator of the squared coefficient of variation ($CV^2$) is derived by using Edgeworth expansions under general population models. Also bias of the estimator is investigated for several important distributions. Under the normal distribution, we proposed the new estimator for $CV^2$ based on median of the sampling distribution of plug-in estimator.

This note deals with the estimations of the variance of a normal distribution $N(\theta,c\theta^2)$ where c, the square of coefficient of variation is assumed to be known. This amounts to the estimation of $\theta^2$. The minimum variance estimator among all unbiased estimators linear in $\bar{x}^2$ and $s^2$ where $\bar{x}$ and $s^2$ are the sample mean and variance, respectively, and the minimum risk estimator in the class of all estimators linear in $\bar{x}^2$ and $s^2$ are obtained. It is shown that the suggested estimators are BAN.

In this paper, we develop the noninformative priors when the parameter of interest is the common coefficient of variation in two inverse Gaussian distributions. We want to develop the first and second order probability matching priors. But we prove that the second order probability matching prior does not exist. It turns out that the one-at-a-time and two group reference priors satisfy the first order matching criterion but Jeffreys' prior does not. The Bayesian credible intervals based on the one-at-a-time reference prior meet the frequentist target coverage probabilities much better than that of Jeffreys' prior. Some simulations are given.

This article deals with the problem of testing mean when the coefficient of variation in normal distribution is known. We propose Bayesian hypothesis testing procedures for the normal mean under the noninformative prior. The noninformative prior is usually improper which yields a calibration problem that makes the Bayes factor to be defined up to a multiplicative constant. So we propose the objective Bayesian hypothesis testing procedures based on the fractional Bayes factor and the intrinsic Bayes factor under the reference prior. Specially, we develop intrinsic priors which give asymptotically same Bayes factor with the intrinsic Bayes factor under the reference prior. Simulation study and a real data example are provided.

When X and Y have independent normal distributions with equal coefficient of variation, we develop the reference priors for different groups of ordering for the parameters. Propriety of posteriors under reference priors proved. A real example is presented to compare the classical estimator and Bayes estimator.

This paper deals with the problem of estimating the means in two inverse Gaussian populations with equal but unknown coefficient of variation. The maximum likelihood estimators are derived by solving a cubic equation and their asymptotic variances are presented for comparative purpose. Monte-Carlo simulation is conducted to investigate the efficiency of the estimators relative to the sample means over a wide range of values for the sample size and the coefficient of variation. The effect on this efficiency under the departure from the assumption of common coefficient of variation is also studied.

Seasonal variation of attenuation coefficient spectra in Japan sea was extracted from underwater radiance/irradiance spectra observed by a moored buoy system developed by National Space Development Agency of Japan (NASDA). The buoy was deployed 9 months from August 31, 1996 to June 1, 1997. Throughout this period, it was collecting downward irradiance and upward radiance spectra under water at the depth of 1.5m and 6.5m everyday. The dairy averaged diffused attenuation coefficient spectra and underwater reflectance spectra were calculated. The results were compared with the absorption spectra of filtered samples obtained by validation cruises, which carried out 5 times during the moored period. Also, the natural fluorescence of chlorophyll a were extracted from the upward radiance spectra observed at 1.5m depth. The seasonal variation of the calculated attenuation coefficient spectra and the natural fluorescence were examined. The result shows a weak blooming of phytoplankton on November and a large blooming on April.

For this study, the sol gel method was used to synthesize the spinel LiNi_0.5Mn_1.5O₄ (LNMO) electrode material. Structural, morphological, electrochemical, and kinetic aspects of the LNMO have been characterized. The synthesized LNMO was indexed with the Fd3m cubic space group. The excellent capacity retention indicates that the spinel framework of LNMO has the ability to withstand high rate charge-discharge throughout long cycle tests. The Li diffusion coefficient (D_Li) changes non-monotonically across three orders of magnitude, from 10^-9 to 10^-12 cm² s^-1 determined from GITT method. The variation of D_Li seemed to be related to three oxidation reactions that happened throughout the charging process. A small dip in D_Li at the beginning stage of Li deintercalation is correlated with the oxidation of Mn³⁺ to Mn⁴⁺. While two pronounced D_Li minima at 4.7 V and 4.75 V are due to the oxidation of Ni²⁺/Ni³⁺ and Ni³⁺/Ni⁴⁺ respectively. The depletion of D_Li at the high voltage region is attributed to the occurrence of two successive phase transformation phenomena.

Experimental studies on both subcooled and saturated pool boiling of water were performed to obtain local heat transfer coefficients on a $3^{\circ}$ inclined tube of 50.8 mm diameter at atmospheric pressure. The local values were determined at every $45^{\circ}$ from the very bottom to the uppermost of the tube periphery. The maximum and minimum local coefficients were observed at the azimuthal angles of $0^{\circ}$ and $180^{\circ}$, respectively, in saturated water. The locations of the maxima and the minima were dependent on the inclination angle of the tube as well as the degree of subcooling. The major heat transfer mechanisms were considered to be liquid agitation generated by the sliding bubbles and the creation of big size bubbles through bubble coalescence. As a way of quantifying the heat transfer coefficients, an empirical correlation was suggested.